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We propose a non-parametric method of smoothing supernova data over redshift using a Gaussian kernel in order to reconstruct important cosmological quantities including H(z) and w(z) in a model independent manner. This method is shown to be…

Astrophysics · Physics 2009-11-24 Arman Shafieloo , Ujjaini Alam , Varun Sahni , Alexei A. Starobinsky

We perform a model independent reconstruction of the cosmic expansion rate based on type Ia supernova data. Using the Union 2.1 data set, we show that the Hubble parameter behaviour allowed by the data without making any hypothesis about…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 S. Benitez-Herrera , E. E. O. Ishida , M. Maturi , W. Hillebrandt , M. Bartelmann , F. Röpke , .

In this work we derive state-of-the-art model-independent constraints on cosmology from SN Ia by measuring purely kinematical $\left( q,j \right)$ model parameters (where $q$ and $j$ are related to the first and second derivative of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-30 Caroline Heneka

Gaussian processes (GPs) have been extensively utilized as nonparametric models for component separation in 21 cm data analyses. This exploits the distinct spectral behavior of the cosmological and foreground signals, which are modeled…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-13 Kangning Diao , Richard D. P. Grumitt , Yi Mao

We have assembled a compilation of observational Hubble parameter measurements estimated with the differential evolution of cosmic chronometers, in the redshift range 0<z<1.75. This sample has been used, in combination with CMB data and…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-06 Michele Moresco , Licia Verde , Lucia Pozzetti , Raul Jimenez , Andrea Cimatti

In this article, we employ a machine learning (ML) approach for the estimations of four fundamental parameters, namely, the Hubble constant ($H_0$), matter ($\Omega_{0m}$), curvature ($\Omega_{0k}$) and vacuum ($\Omega_{0\Lambda}$)…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-10 Srikanta Pal , Rajib Saha

In this paper we reconstruct the growth and evolution of the cosmic structure of the Universe using Markov Chain Monte Carlo algorithms for Gaussian processes [1]. We estimate the difference between the reconstructions that are calculated…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-29 Mauricio Reyes , Celia Escamilla-Rivera

We investigate uncertainties in the estimation of the Hubble constant ($H_0$) arising from Gaussian Process (GP) reconstruction, demonstrating that the choice of kernel introduces systematic variations comparable to those arising from…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-07 Ruchika , Purba Mukherjee , Arianna Favale

Recent analyses of the Master Type Ia supernova (SN Ia) sample have revealed a mild redshift dependence in the inferred local Hubble parameter, often expressed as tilde{H}_0(z) = H_0 (1+z)^{-\alpha}, where \alpha quantifies possible…

General Physics · Physics 2025-11-12 Seokcheon Lee

The Hubble constant ($H_0$) tension between Type Ia Supernovae (SNe Ia) and Planck measurements ranges from 4 to 6 $\sigma$. To investigate this tension, we estimate $H_{0}$ in the $\Lambda$CDM and $w_{0}w_{a}$CDM models by dividing the…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-24 Maria Giovanna Dainotti , Biagio De Simone , Tiziano Schiavone , Giovanni Montani , Enrico Rinaldi , Gaetano Lambiase

We employ the superpotential technique for the reconstruction of cosmological models with a non-minimally coupled scalar field evolving on a spatially flat Friedmann-Robertson-Walker background. The key point in this method is that the…

General Relativity and Quantum Cosmology · Physics 2013-03-08 A. Yu. Kamenshchik , A. Tronconi , G. Venturi , S. Yu. Vernov

Directly comparing the 6 expansion rate measured by type Ia supernovae data and the lower bound on the expansion rate set by the strong energy conditions or the null hypothesis that there never exists cosmic acceleration, we see $3\sigma$…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-06 Yingjie Yang , Yungui Gong

We propose a model-independent formalism to numerically solve the modified Friedmann equations in the framework of $f(T)$ teleparallel cosmology. Our strategy is to expand the Hubble parameter around the redshift $z=0$ up to a given order…

General Relativity and Quantum Cosmology · Physics 2017-11-01 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

We introduce a new sequential methodology to calibrate the fixed parameters and track the stochastic dynamical variables of a state-space system. The proposed method is based on the nested hybrid filtering (NHF) framework of [1], that…

Computation · Statistics 2021-03-24 Sara Pérez-Vieites , Joaquín Míguez

The supernova (SN) Hubble diagram residual contains valuable information on both the present matter power spectrum and its growth history. In this paper we show that this information can be retrieved with precision by combining both…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-10 Tiago Castro , Miguel Quartin , Sandra Benitez-Herrera

We use 21 Hubble parameter versus redshift data points, from Gazta\~{n}aga et al. (2009), Stern et al. (2010), and Moresco et al. (2012), to place constraints on model parameters of constant and time-evolving dark energy cosmologies. This…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Omer Farooq , Data Mania , Bharat Ratra

The Hubble constant ($H_0$) is essential for understanding the universe's evolution. Different methods, such as Affine Invariant Markov chain Monte Carlo Ensemble sampler (EMCEE), Gaussian Process (GP), and Masked Autoregressive Flow (MAF),…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-29 Jing Niu , Jie-Feng Chen , Peng He , Tong-Jie Zhang , Jie Zhang

We reanalyze the recently released SH0ES data for the determination of $H_0$. We focus on testing the homogeneity of the Cepheid+SnIa sample and the robustness of the results in the presence of new degrees of freedom in the modeling of…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-20 Leandros Perivolaropoulos , Foteini Skara

In this paper, a parameterized deceleration parameter $q(z)= 1/2 - a/(1 + z)^b$ is reconstructed from the latest type Ia supernovae gold dataset. It is found out that the transition redshift from decelerated expansion to accelerated…

Astrophysics · Physics 2007-05-23 Lixin Xu , Chengwu Zhang , Baorong Chang , Hongya Liu

(Abridged) We develop median statistics that provide powerful alternatives to chi-squared likelihood methods and require fewer assumptions about the data. Applying median statistics to Huchra's compilation of nearly all estimates of the…

Astrophysics · Physics 2009-10-31 J. Richard Gott , Michael S. Vogeley , Silviu Podariu , Bharat Ratra
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